Recording multiple spatially-heterodyned direct to digital holograms in one digital image

Abstract

Systems and methods are described for recording multiple spatially-heterodyned direct to digital holograms in one digital image. A method includes digitally recording, at a first reference beam-object beam angle, a first spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis; Fourier analyzing the recorded first spatially-heterodyned hologram by shifting a first original origin of the recorded first spatially-heterodyned hologram to sit on top of a first spatial-heterodyne carrier frequency defined by the first reference beam-object beam angle; digitally recording, at a second reference beam-object beam angle, a second spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis; Fourier analyzing the recorded second spatially-heterodyned hologram by shifting a second original origin of the recorded second spatially-heterodyned hologram to sit on top of a second spatial-heterodyne carrier frequency defined by the second reference beam-object beam angle; applying a first digital filter to cut off signals around the first original origin and define a first result; performing a first inverse Fourier transform on the first result; applying a second digital filter to cut off signals around the second original origin and define a second result; and performing a second inverse Fourier transform on the second result, wherein the first reference beam-object beam angle is not equal to the second reference beam-object beam angle and a single digital image includes both the first spatially-heterodyned hologram and the second spatially-heterodyned hologram.

1. A method of obtaining multiple spatially-heterodyned holograms, comprising:
 digitally recording, at a first reference beam-object beam angle, a first spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis; 
 digitally recording, at a second reference beam-object beam angle, a second spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis; 
 Fourier analyzing the recorded first spatially-heterodyned hologram by shifting a first original origin of the recorded first spatially-heterodyned hologram to sit on top of a first spatial-heterodyne carrier frequency defined by the first reference beam-object beam angle; 
 Fourier analyzing the recorded second spatially-heterodyned hologram by shifting a second original origin of the recorded second spatially-heterodyned hologram to sit on top of a second spatial-heterodyne carrier frequency defined by tile second reference beam-object beam angle; 
 applying a first digital filter to cut off signals around the first original origin and define a first result; 
 performing a first inverse Fourier transform on the first result; 
 applying a second digital filter to cut off signals around the second original origin and define a second result; and 
 performing a second inverse Fourier transform on the second result, 
 wherein the first reference beam-object beam angle is not equal to the second reference beam-object beam angle and a single digital image includes both the first spatially-heterodyned hologram and the second spatlally-heterodyned hologram. 
 
   
   
     2. The method of  claim 1 , wherein the spatial heterodyne fringes of the first spatially-heterodyned hologram are substantially orthogonal with respect to the spatial heterodyne fringes of the second spatlally-heterodyned hologram. 
   
   
     3. The method of  claim 1 , wherein a single pixilated detection device is used to digitally record both the first spatially-heterodyned hologram and tile second spatlally-heterodyned hologram. 
   
   
     4. The method of  claim 3 , wherein the single digital image is generated by the single pixilated detection device. 
   
   
     5. The method of  claim 1 , wherein digitally recording the first spatially-heterodyried hologram is performed substantially simultaneously with digitally recording the second spatially-heterodyned hologram. 
   
   
     6. The method of  claim 5 , wherein a first reference beam and a first object beam that define the first reference beam-object beam angle are not coherent with respect to a second reference beam and a second object beam that define the second reference beam-object beam angle. 
   
   
     7. The method of  claim 1 , wherein digitally recording the first spatially-heterodyned hologram is performed before digitally recording the second spatially-heterodyned hologram. 
   
   
     8. The method of  claim 7 , further comprising changing a path of a reference beam after digitally recording the first spatially-heterodyned hologram and before digitally recording the second spatially-heterodyned hologram. 
   
   
     9. The method of  claim 7 , further comprising moving a sample that is characterized by both the first spatially-heterodyned hologram and the second spatially-heterodyned hologram after digitally recording the first spatially-heterodyned hologram and before digitally recording the second spatially-heterodyned hologram. 
   
   
     10. The method of  claim 1 , wherein the first spatially-heterodyned hologram characterizes a first sample and the second spatlally-heterodyned hologram characterizes a second sample.